【摘要】 基于“三维组集式本构模型”［１～３］，运用功共轭原理和场平均方法，发展了一种“取向元”概念——多晶聚集体内具有相同取向的滑移系集的一个体积平均意义上的代表性元素；由一维的率（粘性）敏感“取向元”，通过在取向空间里的积分，获得了三维的弹粘塑性本构方程式，并模拟了蠕变和松弛现象．与以往的粘塑性模型相比，本文模型不仅能同时考虑多晶金属材料的率相关性和路径相关性，而且由于引入了物理机制，因而具有较强的预测能力．数值算例也展示了该模型的合理性更多还原

【Abstract】 An Oriented-Element Theory (OET) originating with one of the present authors, Liang , is developed for studying viscoplastic behaviors of polycrystalline metals subjected to complex loading paths. Application of the work-conjugate principle and the field-average method leads to a concept of “oriented-element”, i.e. a representative or an averaged slip system for those practical slip systems that have the same orientations, from which a concise viscoplastic constitutive equation is derived. A number of numerical examples are given to demonstrate OET′s modeling capability for dynamic loading, and some of the basic characteristics observed in experiments are reproduced, including creep and relaxation. Good agreements are achieved between the predictions and recent experiment reports . The versatility of the theory and its possibility of application to the deformation-induced anisotropic damage and viscosity-damage interaction are also briefly discussed at the end of the paper.更多还原